Re: [ft-devel] More crashes on ARM

[Frank Meerkoetter]

Quoting david turner <address@hidden>:

Hi,

thanks for your explanation.
It seems that FT_CMap_New() isn't called at all.

(gdb) b 'FT_CMap_New'
Function "FT_CMap_New" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y

Breakpoint 1 ('FT_CMap_New') pending.
(gdb) r
Starting program: /root/apdf -qws -f /Doc*/ms*
[Thread debugging using libthread_db enabled]
[New Thread 1024 (LWP 66)]
Breakpoint 2 at 0x409eafcc: file ftobjs.c, line 2329.
Pending breakpoint "'FT_CMap_New'" resolved

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1024 (LWP 66)]
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0x409eb304 in FT_Get_Next_Char (face=0x4bb90, charcode=0,
    agindex=0xbefff748) at ftobjs.c:2436

To verify that this isn't a problem with the debugger i also
placed a printf() inside the FT_CMap_New() function.

Regards,
  Frank


> Sorry, I should have been more accurate.
>
> You should set the watchpoint just after the creation of the FT_CMap
> object (this happens in FT_CMap_New in src/base/ftobjs.c). there is
> code like this:
>
>     if ( !FT_ALLOC( cmap, clazz->size ) )
>     {
>       cmap->charmap = *charmap;
>       cmap->clazz   = clazz;
>
>       if ( clazz->init )
>       {
>         error = clazz->init( cmap, init_data );
>         if ( error )
>           goto Fail;
>       }
>
>       /* add it to our list of charmaps */
>
> you should set the watchpoint after the "cmap->clazz = clazz" statement.
> So it should be:
>
> - first set a breakpoint at the "cmap->clazz = clazz" statement
>   (line 2598 of current CVS)
>
> - when the breakpoint is reached, add a watchpoint to the
>   memory location of the 'clazz' field, i.e.:
>
>      p &cmap->clazz
>      0x6734efd4                          (or some other value)
>      watch *(char*)0x6734efd4   (replace with previous value)
>      c
>
> - repeat each time the first breakpoint is reached (there may be
>   several charmaps in the font)
>
> the watchpoint should trigger whenever the memory location is
> updated. Note that the watchpoint should make things run very
> slowly on some platforms.